<div>
  <div metal:define-macro="test">
    <div metal:define-slot="alternative">
       This is my alternative text which is shown when alternative slot is not filled
    </div>
  </div>

  <div metal:use-macro="test">
    <div metal:fill-slot="alternative">
       I don't want the alternative
    </div>
  </div>

  <div metal:use-macro="test">
     I want the alternative
  </div>
</div>
